, especially when ryan was asked for specifics on romney's call for a 20% across-the-board tax cut. >> you can cut tax rates by 20% and still preserve these important preferences for middle-class taxpayers... >> not mathematically possible. >>t is mathematically possible. it's been done before. it's precisely what we're proposing. >> ( laughs ) it has never been done before. >> it's been done a couple of times, actually. >> it has never been done before. jack kennedy lowered tax rates, increased growth. ronald reagan... >> oh, now, you're jack kennedy. >> woodruff: abortion also figured as a key issue in the debate. both men are catholics, and they were asked to describe their position, based on their faith. >> i don't see how a person can separate their public life from their private life or from their faith. and i respect people who don't agree with me on this. but the policy of a romney administration will be to oppose abortion, with the exceptions for rape, incest, and life of the mother. >> life begins at conception. that's the church's judgment. i accept it in my personal life. i just re